With regards to the maintenance of the front garden, I think you'll find this on your lease. It is the responsibility of the tenant to maintain the upkeep of the property, ie, mowing the lawns and weeding the garden. Some tenancy agreements will cover additional items but, as I say, this should be on your lease. If you don't have a copy, you can request an additional one.
Hmm I'll have to try and find it..... It probably says reasonable state or something, and my reasonable state is probably a lot different to their reasonable state LOL!!!!